Write to a *DEC DTAARA

Hi All,
I define a data area MYDTA *DEC LEN(2  0).
Now I wanna write to it from my program.

DDATA             DS                          DTAARA(MYDTA)
D  field                                      2  0
*
C        *LOCK         IN            DATA
C                           Z-ADD     18                field
C                           OUT        DATA
C                          Move        *on               *inLR

I keep geeting error  RNQ0411 :
 "Data area MYDTA type or length does not match program data area"

It's easy to write to character dataarea, but *DEC give me a headache. I
must miss something!
Pleaseeee.....any hints or clue...!!!  
Thank you in advance.

regards,
Ivan. L
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